js数组操作

1、创建数组

var test = ["Cain", "wish"];或者是 var test = new Array();

2、合并两个数组-contact()

var test1 = ["Cain", "w"];
var test2 = ["nihau", "what", "Dao"];
var test3 = ["luo"];
var children = test1.concat(test2,test3);

3、用数组的元素组成字符串-join()

function myFunction(){
    var fruits = ["Banana", "Orange", "Apple", "Mango"];
    var x=document.getElementById("demo");
    x.innerHTML=fruits.join();
}

4、数组转换成字符串-toString()

function myFunction(){
    var fruits = ["Banana", "Orange", "Apple", "Mango"];
    var str = fruits.toString();
    var x=document.getElementById("demo");
    x.innerHTML= str;
}

5、删除数组的最后一个元素-pop(),第一个元素-shift()

var fruits = ["Banana", "Orange", "Apple", "Mango"];
function myFunction(){
    fruits.pop();
    var x=document.getElementById("demo");
    x.innerHTML=fruits;
}

6、给数组末尾添加新元素-push()

var fruits = ["Banana", "Orange", "Apple", "Mango"];
function myFunction(){
    fruits.push("Kiwi")
    var x=document.getElementById("demo");
    x.innerHTML=fruits;
}

7、数组的排序-sort()

function myFunction(){
    //按字母顺序
    var fruits = ["Banana", "Orange", "Apple", "Mango"];
    fruits.sort();
    //按数字升序
    var points = [40,100,1,5,25,10];
    points.sort(function(a,b){return a-b});
    //按数字降序
    var points = [40,100,1,5,25,10];
    points.sort(function(a,b){return b-a});

}

8、在数组的某个位置添加元素-splice()

function myFunction(){
    var fruits = ["Banana", "Orange", "Apple", "Mango"];
    fruits.splice(2,0,"Lemon","Kiwi");
    var x=document.getElementById("demo");
    x.innerHTML=fruits;
}

9、反转数组顺序-reverse

10、返回数组对象的原始值-valueOf() [注：valueOf()不会改变原来的数组]

var fruits = ["Banana", "Orange", "Apple", "Mango"];
var v=fruits.valueOf();
v==fruits=>true